The present invention relates to a water repellent composition.
As water repellent treatment has become common, the performance required for fibers has been increasingly high. In recent years, it is required that fibers will exhibit a high level of water repellency continuously even under severe conditions in outdoor applications such as mountain climbing and skiing. Against such requirement, the following methods of treating fibers have been proposed.
(1) A method of treating fibers by means of an aqueous dispersion containing a fluorine-containing copolymer and a water-soluble amino resin (such as an N-methylol-modified melamine resin) (JP-A-56-165072).
(2) A method of treating fibers by means of a treating agent comprising a fluorine-containing copolymer and an isocyanate compound (JP-A-61-19684).
(3) A method of treating fibers by means of an aqueous dispersion containing a fluorine-containing copolymer having isocyanate groups and hydroxyl groups, and a blocked isocyanate compound (U.S. Pat. No. 4,834,764).
However, these methods have been still inadequate to realize excellent water repellency and its durability required for fibers at a practical level.
It is an object of the present invention to provide a water repellent composition which is capable of imparting excellent water repellency and its durability to an article such as fibers.
The present invention provides a water repellent composition comprising the following polymer (A) and the following polymer (B), wherein the polymer (A) and the polymer (B) are not present in the same particles:
Polymer (A): an addition polymer comprising at least 60 mass % of polymerized units of the following polymerizable monomer (a) and at most 40 mass % (inclusive of 0 mass %) of polymerized units of the following polymerizable monomer (b), and, if necessary, polymerized units of a polymerizable monomer (x) other than the polymerizable monomers (a) and (b), wherein the total of the polymerized units of the polymerizable monomer (a) and the polymerized units of the polymerizable monomer (b) is at least 70 mass %; and
Polymer (B): an addition polymer comprising less than 60 mass % (inclusive of 0 mass %) of polymerized units of the polymerizable monomer (a) and at least 30 mass % of polymerized units of the following polymerizable monomer (c), and, if necessary, polymerized units of a polymerizable monomer (y) other than the polymerizable monomers (a) and (c), wherein the total of the polymerized units of the polymerizable monomer (a) and the polymerized units of the polymerizable monomer (c) is at least 50 mass %:
Polymerizable monomer (a): a (meth)acrylate having a polyfluoroalkyl group;
Polymerizable monomer (b): a (meth)acrylate having a long chain alkyl group and not having a polyfluoroalkyl group; and
Polymerizable monomer (c): a polymerizable monomer other than the polymerizable monomers (a) and (b), having a SP value of less than 10.
Further, the present invention provides an article treated with such a water repellent composition.
Now, the present invention will be described in detail with reference to the preferred embodiments.
In this specification, acrylic acid and methacrylic acid will generally be represented by (meth)acrylic acid. The same will apply with respect to a representation such as a (meth)acrylate. Further, a polyfluoroalkyl group is represented by a Rf group.
Polymer (A) is an addition polymer comprising at least 60 mass % of polymerized units of the polymerizable monomer (a) and at most 40 mass % (inclusive of 0 mass %) of polymerized units of the polymerizable monomer (b), and, if necessary, polymerized units of a polymerizable monomer (x) other than the polymerizable monomers (a) and (b), wherein the total of the polymerized units of the polymerizable monomer (a) and the polymerized units of the polymerizable monomer (b) is at least 70 mass %. Namely, polymer (A) may not contain polymerized units of the polymerizable monomer (b).
The polymerizable monomer (a) (hereinafter referred to as the monomer (a)) is a (meth)acrylate having a Rf group. The (meth)acrylate having a Rf group means a compound wherein the Rf group is present in the alcohol residue moiety of a (meth)acrylic acid ester.
The Rf group is a group having at least two hydrogen atoms of an alkyl group substituted by fluorine atoms. The carbon number of the Rf group is preferably from 2 to 20, particularly preferably from 6 to 16. If the carbon number is less than 2, the water repellency tends to be low, and if it exceeds 20, the monomer (a) tends to be solid at room temperature, and its sublimation property tends to be high, whereby handling tends to be difficult.
Further, the Rf group may be of a straight chain structure or a branched structure, but a straight chain structure is preferred. In the case of a branched structure, it is preferred that the branched moiety is present at the terminal portion of the Rf group, and the branched moiety is a short chain having a carbon number of from about 1 to 4.
Further, the Rf group may contain, in addition to fluorine atoms, other halogen atoms. As such other halogen atoms, chlorine atoms are preferred. Further, an etheric oxygen atom or a thioetheric sulfur atom may be inserted between a carbonxe2x80x94carbon bond in the Rf group. The structure of the terminal portion of the Rf group may, for example, be CF3CF2xe2x80x94, (CF3)2CFxe2x80x94, CHF2xe2x80x94, CH2Fxe2x80x94 or CCl F2xe2x80x94. CF3CF2xe2x80x94 is preferred.
The number of fluorine atoms in the Rf group is preferably at least 60%, particularly preferably at least 80%, as represented by [(number of fluorine atoms in the Rf group)/(number of hydrogen atoms contained in the corresponding alkyl group having the same carbon number as the Rf group)]xc3x9700(%). As the Rf group, a perfluoroalkyl group (hereinafter referred to as a RF group) is preferred. As the RF group, preferred is a RF group having a straight chain structure i.e. a group represented by F(CF2)ixe2x80x94 (wherein i is an integer of from 2 to 20). Particularly preferred is a group wherein i is an integer of from 6 to 16.
Specific examples of the Rf group will be given below. The following examples include structurally isomeric groups i.e. groups which have the same molecular formula but have different structures.
C4F9xe2x80x94[F(CF2)4xe2x80x94, (CF3)2CFCF2xe2x80x94, (CF3)3Cxe2x80x94], C5F11xe2x80x94[such as F(CF2) 5xe2x80x94 or (CF3)3CCF2xe2x80x94], C6F13xe2x80x94[such as F(CF2)6xe2x80x94], C7F15xe2x80x94, C8H17xe2x80x94, C9F19xe2x80x94, C10F21xe2x80x94, Cl(CF2)txe2x80x94, H(CF2)txe2x80x94 (t is an integer of from 2 to 20), (CF3)2CF(CF2)yxe2x80x94 (y is an integer of from 1 to 17), etc.
Specific examples of a case where the Rf group is a group having an etheric oxygen atom or a thioetheric sulfur atom inserted between a carbonxe2x80x94carbon bond, will be given below, wherein r is an integer of from 1 to 5, z is an integer of from 1 to 6, and w is an integer of from 1 to 9.
F(CF2)5OCF (CF3)xe2x80x94, F[CF(CF3)CF2O]rCF(CF3)CF2CF2xe2x80x94, F[CF(CF3)CF2O]zCF(CF3)xe2x80x94, F[CF(CF3)CF2O]zCF2CF2xe2x80x94, F(CF2CF2CF2O)zCF2CF2xe2x80x94, F(CF2CF2O)zCF2CF2xe2x80x94, etc.
F(CF2)5SCF(CF3)xe2x80x94, F[CF(CF3)CF2S]rCF(CF3)CF2CF2xe2x80x94, F[CF(CF3)CF2S]zCF(CF3)xe2x80x94, F[CF(CF3)CF2S]zCF2CF2xe2x80x94, F(CF2CF2CF2S)zCF2CF2xe2x80x94, F(CF2CF2S)wCF2CF2xe2x80x94, etc.
As the monomer (a), a compound represented by the following formula 1 is preferred. However, in the formula 1, Rf is a Rf group, Q is a bivalent organic group, and R1 is a hydrogen atom or a methyl group.
Rfxe2x80x94Qxe2x80x94OCOCR1xe2x95x90CH2xe2x80x83xe2x80x83Formula 1 
In the formula 1, Q is preferably, for example, xe2x80x94(CH2)p+qxe2x80x94, xe2x80x94(CH2)pCONH(CH2)qxe2x80x94, xe2x80x94(CH2)pOCONH(CH2)qxe2x80x94, xe2x80x94(CH2)pSO2NR2(CH2)qxe2x80x94, xe2x80x94(CH2)pNHCONH(CH2)qxe2x80x94, or xe2x80x94(CH2)pCH(OH)(CH2)qxe2x80x94, wherein R2 is a hydrogen atom or an alkyl group, and each of p and q is an integer of 0 or more, provided that p+q is an integer of from 1 to 22.
Among them, preferred is xe2x80x94(CH2)p+qxe2x80x94, xe2x80x94(CH2)pCONH(CH2)qxe2x80x94 or xe2x80x94(CH2)pSO2NR2(CH2)qxe2x80x94, wherein q is an integer of at least 2, provided that p+q is from 2 to 6. Particularly preferred is xe2x80x94(CH2)p+qxe2x80x94 wherein p+q is from 2 to 6, i.e. a dimethylene group, a trimethylene group, a pentamethylene group or a hexamethylene group. Further, it is preferred that fluorine atoms are bonded to the carbon atom of Rf bonded to Q.
The following compounds may preferably be mentioned as specific examples of the monomer (a), wherein R1 is a hydrogen atom or a methyl group.
F(CF2)2(CH2)2OCOCR1xe2x95x90CH2,
F(CF2)4 (CH2)2OCOCR1xe2x95x90CH2,
F(CF2)5CH2OCOCR1xe2x95x90CH2,
H(CF2)6CH2OCOCR1xe2x95x90CH2,
F(CF2)6(CH2)2OCOCR1xe2x95x90CH2,
H(CF2)8CH2OCOCR1xe2x95x90CH2,
H(CF2)8(CH2)2OCOCR1xe2x95x90CH2,
F(CF2)8(CH2)3OCOCR1xe2x95x90CH2,
F(CF2)8 (CH2)4OCOCR1xe2x95x90CH2,
F(CF2)9 (CH2)2OCOCR1xe2x95x90CH2,
H(CF2)10CH2OCOCR1xe2x95x90CH2,
F(CF2)10(CH2)2OCOCR1xe2x95x90CH2,
F(CF2)12(CH2)2OCOCR1xe2x95x90CH2,
(CF3)2CF(CF2)4(CH2)2OCOCR1xe2x95x90CH2,
(CF3)2CF(CF2)6(CH2)2OCOCR1xe2x95x90CH2,
(CF3)2CF(CF2)8(CH2)2OCOCR1xe2x95x90CH2,
F(CF2)8SO2N(CH3)(CH2)2OCOCR1xe2x95x90CH2,
F(CF2)8SO2N(C2H5)(CH2)2OCOCR1xe2x95x90CH2,
F(CF2)8SO2N(C3H7)(CH2)2OCOCR1xe2x95x90CH2,
F(CF2)8CONH(CH2)2OCOCR1xe2x95x90CH2,
F(CF2)gCONH(CH2)2OCOCR1xe2x95x90CH2,
(CF3)2CF(CF2)5(CH2)3OCOCR1xe2x95x90CH2,
(CF3)2CF(CF2)5CH2CH(OCOCH3)OCOCR1xe2x95x90CH2,
(CF3)2CF(CF2)5CH2CH(OH)CH2OCOCR1xe2x95x90CH2,
(CF3)2CF(CF2)7CH2CH(OH)CH2OCOCR1xe2x95x90CH2.
The monomer (a) may be two or more (meth)acrylates having Rf groups. In such a case, they are preferably (meth)acrylates having Rf groups having different carbon numbers.
The polymerizable monomer (b) (hereinafter referred to as a monomer (b)) is a (meth)acrylate having a long chain alkyl group and having no Rf group. The (meth)acrylate having a long chain alkyl group is a compound wherein a long chain alkyl group is present in the alcohol residue moiety of a (meth)acrylic acid ester. The long chain alkyl group is preferably an alkyl group of a straight chain structure having a carbon number of at least 12.
As specific examples of the monomer (b), dodecyl (meth)acrylate, hexadecyl (meth)acrylate, octadecyl (meth)acrylate, icosyl (meth)acrylate, docosyl (meth)acrylate and tetracosyl (meth)acrylate are preferably mentioned. The monomer (b) may be two or more polymerizable monomers having long chain alkyl groups and having no Rf group.
In a case where polymer (A) contains polymerized units of the monomer (b), the mass ratio of polymerized units of the monomer (a)/polymerized units of the monomer (b) is preferably at least 2.
If necessary, polymer (A) may contain polymerized units of a polymerizable monomer (x) (hereinafter referred to as a monomer (x)) other than the polymerized monomers (a) and (b). At least one type of polymerized units of such a monomer (x) is preferably polymerized units of the polymerizable monomer (c). The polymerizable monomer (c) (hereinafter referred to as a monomer (c)) is a polymerizable monomer having a SP value of less than 10 and is a monomer other than the monomer (a) or (b).
As a calculation method for the SP value, a method by Fedors (1974) is employed. Namely, when the cohesive energy of each constituting unit of the monomer is represented by e and the molar volume by v, the cohesive energy E of the monomer is calculated by E=xcexa3e, the molar volume V by V=xcexa3v, and the SP value xcex4 by xcex4=(E/V)
As specific examples of the monomer (c), 2-ethylhexyl (meth)acrylate[8.6], methyl (meth)acrylate[8.9], n-butyl (meth)acrylate[8.8], t-butyl (meth)acrylate[8.4], 2-(dimethylamino)ethyl (meth)acrylate[8.9], cyclohexyl (meth)acrylate[9.6], isobonyl (meth)acrylate[9.8], polyoxypropylene mono(meth)acrylate[8.7], and vinyl chloride[8.5] may preferably be mentioned. The numerals in the brackets [ ] are SP values. As the monomer (c), two or more monomers may be used in combination.
In the polymer (A), the proportion of polymerized units of the monomer (c) is preferably at most 30 mass %, and the total of polymerized units of the monomer (a), polymerized units of the monomer (b) and polymerized units of the monomer (c), is preferably at least 90 mass %.
Polymer (A) may contain polymerized units of a polymerizable monomer (hereinafter referred to as a monomer (e)) other than the monomer (a), the monomer (b) and the monomer (c). As the monomer (e), a polymerizable monomer having one or two polymerizable unsaturated groups, is preferred. Particularly preferred is a polymerizable monomer having one polymerizable unsaturated group.
As specific examples of the monomer (e), diacetone (meth)acrylamide[10.9], N,N-dimethyl (meth)acrylamide[10.5], benzyl (meth)acrylate [10.1], and vinylidene chloride[10.3], may preferably be mentioned. The numerals in the brackets [ ] are SP values.
The mass average molecular weight of polymer (A) is preferably from 5xc3x97103 to 5xc3x97106.
As a polymerization method to obtain polymer (A), emulsion polymerization or suspension polymerization is preferred. Particularly preferred is emulsion polymerization. The emulsion polymerization is preferably carried out by a method wherein the polymerizable monomer is emulsified by means of an aqueous medium such as water or a mixed medium of water and an alcohol, followed by polymerization. By such emulsion polymerization or the like, polymer (A) is obtained in a state dispersed in the form of particles in the aqueous medium (in a dispersion). As such emulsification method, high pressure emulsification by means of a homogenizer may be employed.
As the alcohol in the aqueous medium, ethanol, isopropyl alcohol, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, dipropylene glycol monomethyl ether, tripropylene glycol or hexylene glycol may, preferably, be mentioned.
In the polymerization reaction to obtain polymer (A), it is preferred to employ an oil-soluble polymerization initiator. As the oil-soluble polymerization initiator, a peroxide or an azo type compound is preferred. Particularly preferred is an azo type compound. As the azo type compound, 2,2xe2x80x2-azobis(2-methylpropionitrile), 2,2xe2x80x2-azobis(2-methylbutyronitrile), 2,2xe2x80x2-azobis(2,4-dimethylvaleronitrile), 1,1xe2x80x2-azobis(cyclohexane-1-carbonitrile) or dimethyl 2,2xe2x80x2-azobis(2-methylpropionate) may, for example, be preferably mentioned.
Further, in the polymerization reaction, a molecular weight controlling agent, for example, a mercaptan such as dodecylmercaptan, octadecylmercaptan or 2-hydroxyethylmercaptan, or xcex1-methylstyrene dimer, may be added for the purpose of controlling the molecular weight of polymer (A) to be obtained.
An emulsifier may be present in the dispersion of polymer (A).
As such an emulsifier, a nonionic emulsifier, a cationic emulsifier or an amphoteric emulsifier is preferred. Particularly preferred is a non-ionic emulsifier.
The nonionic emulsifier may, for example, be a polyoxyethylene alkenyl ether, a polyoxyethylene alkyl ether, a polyoxyethylene alkyl phenyl ether, a polyoxyethylene polyoxyalkylene, an alkylamine polyoxyethylene, an alkylamide polyoxyethylene or an alkylamine oxide. Further, as the alkyl moiety in the above compound, an alkyl group of a straight chain structure or a branched structure having a carbon number of from 4 to 26 may be mentioned. Specifically, an octyl group, a dodecyl group, a tetradecyl group, a hexadecyl group, an octadecyl group or a behenyl group, may, for example, be mentioned.
As a specific example of the polyoxyethylene alkenyl ether, polyoxyethylene oleyl ether may be mentioned. As a specific example of the polyoxyethylene alkyl ether, polyoxyethylene octyl ether may be mentioned. As a specific example of the polyoxyethylene alkyl phenyl ether, polyoxyethylene octyl phenyl ether or polyoxyethylene nonyl phenyl ether may be mentioned.
The cationic emulsifier may, for example, be an amine salt, a quaternary ammonium salt or an oxyethylene-addition type quaternary ammonium salt. Specifically, a trimethylalkylammonium chloride, a dimethyldialkylammonium chloride, a monoalkylamine acetate, or an alkylmethyldi(polyoxyethylene)ammonium chloride may be mentioned. Preferred is octadecyltrimethylammonium chloride.
The amphoteric emulsifier may, for example, be an alanine, an imidazolinium betain, an amide betain or betain acetate. Specifically, dodecylbetain, octadecylbetain, dodecylcarboxymethyl hydroxyethylimidazolinium betain, betain dodecyldimethylaminoacetate or betain fatty acid amidepropyldimethylaminoacetate may, for example, be mentioned.
As the emulsifier, one type, or two or more types, may be used. When emulsifiers having different ionic properties are to be used in combination, a combination of a nonionic surfactant and a cationic surfactant, or a combination of a nonionic surfactant and an amphoteric surfactant, is preferred. Further, the amount of the emulsifier is preferably from 1 to 20 parts by mass, per 100 parts by mass of polymer (A). However, when polymer (A) contains a polymerizable monomer having a self emulsifying property, the amount of the emulsifier may be reduced.
The average particle size of polymer (A) is preferably from 0.03 to 0.3 xcexcm. If the average particle size is less than 0.03 xcexcm, a large amount of an emulsifier or a polymerizable monomer having a self emulsifying property, will be required to obtain a stable dispersion, and the water repellency tends to low. On the other hand, if it exceeds 0.3 xcexcm, particles are likely to settle.
Polymer (B) is an addition polymer comprising less than 60 mass % (inclusive of 0 mass %) of polymerized units of the monomer (a) and at least 30 mass % of polymerized units of the monomer (c), and, if necessary, polymerized units of a polymerizable monomer (y) other than the monomers (a) and (c), wherein the total of the polymerized units of the monomer (a) and the polymerized units of the monomer (c) is at least 50 mass %. In polymer (B), the polymerized units of the monomer (a) is preferably at most 40 mass %, and no polymerized units of the monomer (a) may be contained.
In a case where polymer (B) contains polymerized units of the monomer (a), the monomer (a) has the same meaning as the monomer (a) in polymer (A). The monomer (a) in polymer (B) may be the same or different from the monomer (a) in polymer (A), or two or more monomers (a) may be used in combination.
The monomer (c) in polymer (B) has the same meaning as the monomer (c) in polymer (A). The monomer (c) in polymer (B) may be the same or different from the monomer (c) in polymer (A), or two or more monomers (c) may be used in combination.
If necessary, polymer (B) may contain polymerized units of a polymerizable monomer (y) (hereinafter referred to as a monomer (y)) other than polymerizable monomers (a) and (c). At least one type of polymerized units of the monomer (y) is preferably polymerized units of a polymerizable monomer (d). The polymerizable monomer (d) (hereinafter referred to as a monomer (d)), is a (meth)acrylic acid derivative compound having a cross-linkable functional group and is a monomer other than the monomer (b).
The cross-linkable functional group in the monomer (d) may, for example, be an epoxy group, a carboxyl group, an amino group, a silyl group, an isocyanate group, a blocked isocyanate group, an N-methylol group or a hydroxyl group.
The monomer (d) may, for example, be preferably diglycidyl (meth)acrylate, 3-chloro-2-hydroxypropyl (meth)acrylate, (meth)acrylic acid, mono-2-(meth)acryloyloxyethyl succinate [CH2xe2x95x90C(CH3)COOCH2CH2OCOCH2CH2COOH], an oxime block product of 2-isocyanate ethyl (meth)acrylate, N-methylol (meth)acrylamide, N-butyrol (meth)acrylamide, 2-hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, diacetone (meth)acrylamide, or N,N-dimethyl (meth)acrylamide.
Polymer (B) may contain two or more types of polymerized units of the monomer (d).
The mass average molecular weight of polymer (B) is preferably from 5xc3x97103 to 5xc3x97106.
As a polymerization method to obtain polymer (B), emulsion polymerization or suspension polymerization may, for example, be preferred. Particularly preferred is emulsion polymerization. By such emulsion polymerization or the like, polymer (B) is obtained in a state dispersed in the form of particles in an aqueous solvent (in a dispersion).
The emulsion polymerization is preferably carried out by means of a polymerization initiator. As such a polymerization initiator, a peroxide or an azo type compound is preferred. Particularly preferred is an azo type compound. The azo type compound may, for example, be an oil-soluble polymerization initiator as described with respect to polymer (A), or a water-soluble polymerization initiator such as 2,2xe2x80x2-azobis(2-methylpropionamidine) hydrochloride, 2,2xe2x80x2-azobis[2-(2-imidazolin-2-yl)propane] hydrochloride or 2,2xe2x80x2-azobis[2-(2-imidazolin-2-yl)propane] sulfate hydrate.
Further, a molecular weight controlling agent may be added at the time of the polymerization reaction for the purpose of controlling the molecular weight of polymer (B) to be obtained. As such a molecular weight controlling agent, the molecular weight controlling agent as mentioned in the description of polymer (A) may preferably be employed.
An emulsifier may be present in the dispersion of polymer (B).
As the emulsifier, the nonionic emulsifier, the cationic emulsifier or the amphoteric emulsifier, as described with respect to polymer (A), is preferred. Particularly preferred is a nonionic emulsifier.
As the emulsifier, one type, or two or more types, may be used. In a case where emulsifiers having different ionic properties, are used in combination, a combination of a nonionic emulsifier and a cationic emulsifier, or a combination of a nonionic emulsifier and an amphoteric emulsifier, is preferred. Further, the amount of the emulsifier is preferably from 1 to 20 parts by mass per 100 parts by mass of polymer (B). However, in a case where polymer (B) contains a polymerizable monomer having a self-emulsifying property, the amount of the emulsifier may be reduced.
The average particle size of polymer (B) is preferable from 0.03 to 0.3 xcexcm. If the average particle size is less than 0.03 xcexcm, a large amount of the emulsifier or the polymerizable monomer having a self-emulsifying property, will be required to obtain a stable dispersion, and the water repellency tends to be low. On the other hand, if it exceeds 0.3 xcexcm, particles are likely to settle.
In the water repellent composition of the present invention, polymer (A) and polymer (B) are not present in the same particles and constitute separate particles, respectively. It is preferred to prepare the water repellent composition of the present invention by carrying out separate polymerization reactions to obtain polymer (A) and polymer (B), respectively, to form separate particles thereby to obtain respective dispersion and then mixing the respective dispersions.
In the water repellent composition, the mass ratio of polymer (A) to polymer (B) is preferably (A)/(B)=10/90 to 90/10, particularly preferably 20/80 to 80/20. If the ratio of polymer (A) to polymer (B) is within the above range, the composition will be excellent in water repellency and also in durability of the water repellency. Further, the solid content concentration is preferably from 0.1 to 50 mass parts.
In order to provide various physical properties to an article such as a fiber product, a polymer other than polymer (A) or (B), a water repellent, an oil repellent, a catalyst to accelerate crosslinking, a drape-controlling agent, an antistatic agent, a penetrant, an insecticide, a flame retardant, an anticrease-shrink proofing agent, a dye-stabilizer or pH-controlling agent, may, for example, be incorporated, as the case requires, to the water repellent composition of the present invention.
The water repellent composition of the present invention may be diluted to an optional concentration and applied to an article, depending upon the particular purpose or application. For its application to an article, an optional method may be employed depending upon the type of the article, the formulation of the composition, etc. For example, a method may be employed wherein it is deposited on the surface of an article by a covering method such as dipping or coating, followed by drying. Further, if necessary, it may be applied together with a suitable crosslinking agent, and heat treatment may be carried out.
As a method for treating an article for water repellency, a method of immersing the article in the water repellent composition comprising polymer (A) and polymer (B), is preferred. Also preferred is a water repellent treating method wherein an article is immersed in a composition containing polymer (B) and not containing polymer (A) and then immersing it in a composition containing polymer (A) and not containing polymer (B), since substantially the same effects can be obtained.
The article to be treated by means of the water repellent composition of the present invention is not particular limited, and it may, for example, be preferably fibers, fiber fabrics or fiber knitted products. The fibers may, for example, be animal or plant natural fibers such as cotton, hemp, wool and silk, synthetic fibers such as polyamide, polyester, polyvinyl alcohol, polyacrylonitrile, polyvinyl chloride and polypropylene, semisynthetic fibers such as rayon and acetate, inorganic fibers such as glass fibers and carbon fibers, or mixed fibers thereof.
The article treated with the water repellent composition of the present invention has excellent water repellency and is excellent also in the durability of the water repellency.
Now, the present invention will be described with reference to Preparation Examples (Examples 1 to 4, 24 and 25 (Preparation Examples for polymer (A)), and Examples 6 to 8 and 26 (Preparation Examples for polymer (B))), Comparative Examples (Example 5 (Comparative Preparation Example for polymer (a)), and Examples 9 and 10 (Comparative Preparation Examples for polymer (B))) Working Examples (Examples 11 to 16, 23 and 27 to 29), and Comparative Examples (Examples 17 to 22).